DNR News

March 11, 2013

Bat disease white-nose syndrome confirmed in South Carolina

The S.C. Department of Natural Resources recently received confirmation that white-nose syndrome, a disease that has killed millions of bats in eastern North American, is now officially in South Carolina.

Until now, South Carolina appeared to be insulated from white-nose syndrome (WNS). However, a dead bat discovered recently at Table Rock State Park in northern Pickens County has been confirmed to have WNS, which spreads mainly through bat-to-bat contact and has not been found to infect humans or other animals.

"We have been expecting WNS in South Carolina," said Mary Bunch, wildlife biologist with the S.C. Department of Natural Resources (DNR) based in Clemson. "We have watched the roll call of states and counties and Canadian provinces grow each year since the first bat deaths were noted in New York in 2007." Estimates of bat mortality from WNS in North America range from 5.7-6.7 million bats since the new pathogen was first discovered.

Table Rock State Park staff informed Bunch about what appeared to be a dead bat and asked whether it should undergo WNS testing. Bunch was doing routine WNS monitoring in the area and collected the bat, a tri-colored bat. The bat was collected on Feb. 21, transported on ice, and submitted to the Southeastern Cooperative Wildlife Disease Study in Athens, Ga. The Wildlife Disease Study confirmed the presence of Geomyces destructans fungus, which causes WNS.

Table Rock's bat colony is in a remote portion of the park not accessible to the public, and the discovery of the white-nose syndrome bat is not a threat to park visitors’ health and safety and will not have any negative effects upon their visits to Table Rock State Park.

With the addition of South Carolina, WNS has now been confirmed in 21 states and five Canadian provinces.

Currently there is no cure or effective treatment for WNS, and mortality in some species, such as the small tri-colored bat, has exceeded 98 percent. Bats have very low reproductive rates so recovery from losses takes a long time. Formerly common bats are becoming rare, and some rare bats may be lost. The fungus grows best in a cool moist environment, the same places bats go to hibernate.

Bat species that hibernate in mines or caves are susceptible to WNS. In South Carolina, those species are big brown bat, little brown bat, Eastern small-footed bat, Northern long-eared bat, tricolored bat and Southeastern bat.

In the Southeast, there are some other colonial, non-hibernating, bats in which WNS has not been detected, such as the free-tailed bat and the evening bat.

While WNS is not harmful to humans, scientists believe it is possible for humans to transport fungal spores on clothing and gear. In 2009, the U.S. Fish and Wildlife Service advised cavers and researchers to curtail caving activities and implement decontamination procedures in an effort to reduce the spread of WNS. The fungus cannot be killed simply by washing clothing.

Bats play a critical role in maintaining healthy ecosystems and have an enormous impact on pest control, benefitting the economies of both forestry and agriculture in the United States. For example, the one million little brown bats that have already died due to WNS would have eaten between 660 and 1,320 metric tons of insects in one year. A recent study published in Science estimates that insect-eating bats provide a significant pest-control service, saving the U.S. agricultural industry at least $3 billion a year.

"The news that white-nose syndrome has been confirmed in South Carolina is devastating for these very important mammals," Bunch said. "We will continue to work closely with our partners to understand the spread of this deadly disease and to help minimize its impacts to affected bat species."